This is my first time posting in Zam's FFXIV feedback forum, but I thought I'd make my suggestion here and also see what the community's thoughts on this idea is. I'm sorry this post is so long!
Back in FFXI, I loved my Mog House. I'd hang out there, chatting with my LS members and ogling all the items and furniture that I'd accumulated. I never got into gardening or mannequins much, but I have many friends who were, and who miss these features in FFXIV. In any case, I'd love for a private residence to become available to me in FFXIV, although I'd like it to improve upon the Mog House system in a number of ways.
The FFXIV house system as I currently imagine it would give users their own small but upgradeable house in one of the main cities or hamlets (accessible from one of the currently closed-off areas, or as a selectable zone from where one accesses the Market Wards). The basic house would be on a private plot of land (you can run around the outside of the house too, but it would be in a fenced enclosure, a private zone that gives the illusion of being in a neighborhood). While it would be neat to have homes in non-instanced zones, that poses other problems and would be a pain to implement this late in development.
However, the house would be upgradeable to build other facilities and additions and accommodate other modes of play.
For example, as a Blacksmith I would want to use my guild marks to install a forge, giving me access to smithing support when I insert a fire shard into it (more advanced forges give more advances bonuses). I can also invest in tongs to use while synthing (much like a crafting ability, but only available when using your personal forge and they don't need to be equipped), that would help to stop unstable fire elements. I envision a variety of items available to purchase, each with tiers (for example, from Rusty Tongs to Master Tongs, Worn Heat Gloves to Master Heat Gloves etc).
Another good example would be for Botanists, and implementing the ability to grow plants and crops in your private home. This could be an updated relative to FFXI, and it could allow some level of SP/EXP gains for a successful harvest. Players would be able to purchase seeds and plant them, water them with crystals, etc. Ideally, the player's private house could come with a backyard for gardening (which leads to cool systems of enriching the soil with crystals), but pots again are fine too.
I can see similar minigames available for the other jobs (Miners can grow crystals or... something; Fishermen can raise and breed fish; Shepherds (please release this class!) can raise animals in barns and so forth...). It would be great to implement other minigames for the DoH as well, in order to break up the grind with other things to do and goals to achieve.
The way I'm imagining it, upgrades would be pretty expensive, some would require the player to be a certain level with a certain class, and some upgrades could even be quest rewards.
In any case, these are just my suggestions, feel free to nitpick over them as you wish. I'd love to explore how such a system would work into the framework of Companies, but as it is the thought of being able to own and upgrade my own space and do a variety of things in it would bring in a pretty neat aspect to the game that I'm sure some players would also love.
Thanks for your time!